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| author | KP Singh <kpsingh@google.com> | 2020-06-22 00:21:35 +0200 |
|---|---|---|
| committer | James Morris <jmorris@namei.org> | 2020-06-24 01:39:23 +0200 |
| commit | 23e390cdbe6f85827a43d38f9288dcd3066fa376 (patch) | |
| tree | a08d76e08595224eee8ae4e44bfd238200ee3002 /security | |
| parent | security: fix the key_permission LSM hook function type (diff) | |
| download | linux-23e390cdbe6f85827a43d38f9288dcd3066fa376.tar.xz linux-23e390cdbe6f85827a43d38f9288dcd3066fa376.zip | |
security: Fix hook iteration and default value for inode_copy_up_xattr
inode_copy_up_xattr returns 0 to indicate the acceptance of the xattr
and 1 to reject it. If the LSM does not know about the xattr, it's
expected to return -EOPNOTSUPP, which is the correct default value for
this hook. BPF LSM, currently, uses 0 as the default value and thereby
falsely allows all overlay fs xattributes to be copied up.
The iteration logic is also updated from the "bail-on-fail"
call_int_hook to continue on the non-decisive -EOPNOTSUPP and bail out
on other values.
Fixes: 98e828a0650f ("security: Refactor declaration of LSM hooks")
Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'security')
| -rw-r--r-- | security/security.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/security/security.c b/security/security.c index 0ce3e73edd42..70a7ad357bc6 100644 --- a/security/security.c +++ b/security/security.c @@ -1414,7 +1414,22 @@ EXPORT_SYMBOL(security_inode_copy_up); int security_inode_copy_up_xattr(const char *name) { - return call_int_hook(inode_copy_up_xattr, -EOPNOTSUPP, name); + struct security_hook_list *hp; + int rc; + + /* + * The implementation can return 0 (accept the xattr), 1 (discard the + * xattr), -EOPNOTSUPP if it does not know anything about the xattr or + * any other error code incase of an error. + */ + hlist_for_each_entry(hp, + &security_hook_heads.inode_copy_up_xattr, list) { + rc = hp->hook.inode_copy_up_xattr(name); + if (rc != LSM_RET_DEFAULT(inode_copy_up_xattr)) + return rc; + } + + return LSM_RET_DEFAULT(inode_copy_up_xattr); } EXPORT_SYMBOL(security_inode_copy_up_xattr); |